1. Field of the Invention:
The present invention relates to an image forming apparatus for being mounted on a vehicle, and more particularly to a vibration isolation structure for preventing vibrations from being transmitted from a vehicle to an exposure unit of an image forming apparatus that is mounted on the vehicle.
2. Description of the Related Art:
There have heretofore been known image forming apparatus for recording radiation image information of a subject such as a human body on a stimulable phosphor sheet having a stimulable phosphor layer. A stimulable phosphor is a phosphor which, when exposed to an applied radiation (X-rays, α-rays, β-rays, γ-rays, electron beams, ultraviolet radiation, or the like), stores part of the energy of the radiation, and, when subsequently exposed to applied stimulating rays such as visible light, emits photostimulated luminescence in proportion to the stored energy of the radiation.
An image forming apparatus disclosed in Japanese Laid-Open Patent Publication No. 2001-299743 is installed on a vehicle such as a mobile medical examination car and mounted on the chassis of the mobile medical examination car. The disclosed image forming apparatus can take pictures of subjects for medical examination within the vehicle and at remote sites.
Generally, image forming apparatus for use on vehicles have optical systems that are subject to vibrations. For example, Japanese Laid-Open Patent Publication No. 2001-299743 discloses an image forming apparatus comprising a medical image scanner for scanning patient's bodies. When the image forming apparatus is installed on a vehicle, the optical system thereof is subject to vibrations from the wheels of the vehicle while the vehicle is being driven or vibrations from the engine or electric generator on the vehicle, and may tend to decrease in function.
Heretofore, the image forming apparatus for use on vehicles have not been equipped with a vibration suppressing mechanism for blocking vibrations from being applied from the vehicle to the optical system. Consequently, since the optical system decreases more in function as the resolution of the image forming unit of the image forming apparatus for reading images is higher, it has been difficult to install highly accurate image forming apparatus on vehicles.
Japanese Laid-Open Patent Publication No. 2002-255279 discloses a vibration isolation means for isolating vibrations that are produced on a workpiece that is conveyed. The disclosed vibration isolation means is disposed between a base plate for holding a box such as a container or the like carried by an aircraft or the like and the floor of the aircraft, and isolates vibrations against transmission to the box. When the floor is vibrated, the vibration isolation means suppresses vibrations transmitted from the floor to the base, thereby preventing vibrations from being transmitted to the box.
There have not been available in the art image forming apparatus for use on vehicles which have vibration isolation means for preventing vibrations generated when the vehicles are driven from being transmitted to the image forming apparatus. There has been a demand for carrying a high-precision image forming apparatus which is susceptible to vibrations on a vehicle such as a mobile medical examination car or the like and capturing images of subjects such as patients or the like at remote locations with the image forming apparatus.
In order to prevent vibrations from occurring in an image forming apparatus carried on a vehicle, it may be proposed to install an image forming apparatus, rather than a box such as a container or the like, on the base plate disclosed Japanese Laid-Open Patent Publication No. 2002-255279, and place the base plate on the floor of the vehicle. With this proposed arrangement, it may be possible to prevent vibrations from being transmitted to the image forming apparatus with the vibration isolation means disposed between the base plate and the floor.
However, the disclosed vibration isolation means for preventing vibrations from being transmitted is large in size as it is designed for use on an aircraft. It is difficult to apply the disclosed vibration isolation means to image forming apparatus for use on a vehicle such as mobile medical examination car or the like, and the disclosed vibration isolation means itself is highly costly to manufacture.